1. Field of the Invention
The present invention relates to an occupant""s knee protection system for protecting the knee of an occupant when a vehicle crashes.
2. Description of Related Art
An energy absorbing steering system has conventionally been used in vehicles which enables the axial contraction of a steering shaft and a steering column to absorb impact energy applied to an occupant in order to protect the occupant when a vehicle crashes. A column protector protects the steering column to prevent the knees of the occupant from contacting the steering column when the vehicle crashes. This prevents the contracting operation of the steering system from being disturbed.
Japanese Utility Model Provisional Publication No. 1-73464, for example, discloses a system for protecting the knees of an occupant by preventing the knees from contacting a steering column when a vehicle crashes. In this protection system, a curved protector is provided at the driver""s seat side of a tilt bracket, and this protector is comprised of a steering column and a plate, which is supported and fixed by a substantially Z-shaped stay. The surface of the protector at the driver""s seat side is coated with an urethane layer and a cover in order to prevent the knees and legs of the occupant from directly colliding with the tilt bracket when the vehicle crashes. This reduces the impact energy that is applied to the knees and legs.
If the occupant is of small stature, there is only a small distance between the right and left knees. Thus, depending on the layout of a vehicle, the knees may collide with the steering column when the vehicle crashes, and this results in an insufficient absorption of the energy and an increase in the load applied to the knees. The protection system, whose protector is comprised of the steering column and the plate supported and fixed by the substantially Z-shaped stay, is attached to the steering column, which deforms and moves toward the front of the vehicle when the vehicle crashes. Accordingly, the protector also moves toward the front of the vehicle when the occupant collides with the protector, and this results in an insufficient reduction of the impact energy by the deformation of the protector. It is therefore difficult to satisfactorily absorb the impact load applied to the knees. Moreover, the knees may collide with the steering column as well as the deformed protector, and this disturbs the contracting operation of the steering column.
It is therefore an object of the present invention to provide an occupant""s knee protection system, which absorbs the impact energy applied to the knees by knee absorbers when a vehicle crashes.
The above object can be accomplished by providing an occupant""s knee protection system comprising: a column support fixed to a deck cross member extending along a width of a vehicle; a steering column supported by the column support; a column bracket disposed about an axis of the steering column in such a manner as to widen toward a front part of the vehicle, both ends of the column bracket being fixed to a body of the vehicle; and knee absorbers disposed at both sides of the column bracket, each of the knee absorbers having a base end fixed to the deck cross member and a front end facing the knees of an occupant, the front end coming into contact with the knees of the occupant; wherein when the vehicle crashes, the column bracket guides the knees of the occupant to the knee absorbers, and the knee absorbers absorb impact energy applied to the knees of the occupant.
According to this occupant""s knee protection system, the occupant seated in the driver""s seat moves forward when the vehicle crashes, and the knees move forward accordingly to collide with the column bracket. Since both ends of the column bracket are fixed to the body, the column bracket never deforms if it collides with the knees of the occupant. This prevents the deformation of the steering column, and prevents the contracting function of the steering system for absorbing the impact energy from being disturbed. On the other hand, the column bracket is formed in such a manner as to widen toward the front of the vehicle. Thus, the right and left knees of the occupant move forward along the surface of the column bracket and are guided to the right and left knee absorbers disposed at both sides of the column bracket. When the knee absorbers collide with the knees, they buckle and deform to absorb the impact energy and reduce the knee load. This protects the knees of the occupant.
Therefore, if the vehicle crashes while an occupant with a small distance between the knees is driving, the column bracket can guide the knees of the occupant to the knee absorbers. The knee absorbers can satisfactorily absorb the impact energy applied to the knees to thereby protect the knees. Moreover, since the column bracket and the knee absorbers are fixed to the deck cross member that never moves to the front of the vehicle even when the vehicle crashes, the knees of the occupant can be guided satisfactorily to enable the efficient absorption of the impact energy.
In one preferred mode of the present invention, the knee absorbers are made of a plate member that deforms toward a front of said vehicle due to contact with the knee of the occupant. The knee absorbers preferably have at least one bend part, which is crank-shaped. Therefore, the contact between the knee absorbers and the knees of the occupant results in the effective absorption of the impact energy.
In another preferred mode of the present invention, the knee absorbers are covered with an undercover formed of a resin member. In yet another preferred mode of the present invention, the column bracket is substantially U-shaped and has a bottom part at a rear part of the vehicle and an end part at a front part of the vehicle.
In yet another preferred mode of the present invention, the column bracket is substantially V-shaped in such a manner as to widen from a rear part of the vehicle toward a front part of the vehicle. In yet another preferred mode of the present invention, a reinforcing bead is formed at a longitudinal side of the column bracket.